Oftentimes with electrical connectors, particularly those of the linear variety in which the plug and receptacle of the connector are demated without the need for rotation of the plug with respect to the receptacle, there is need for emergency release to decouple the connector when some force exceeding a selected force is exerted axially upon the plug or receptacle portion of the connector. For example, if a locking ring should jam and emergency disconnection is necessary, an immediate releasing means may be necessary to effect disconnection.
Another example might be in an umbilical connector or a connector to a detachable aircraft service module, e.g., a weapons pod designed to separate from the aircraft. These are typically disconnected by some mechanical means operated by the tugging force of separation upon a lanyard. Should this fail to effect disconnection of the connector, serious consequences could arise, e.g., a dangling service pod which could prevent landing of the aircraft or a severing of the umbilical cord in lieu of decoupling the connector.
It has been known in the past to try to alleviate this problem by providing for emergency release mechanisms which will allow a portion of the connector to come apart when an appropriately large force is exerted, indicating that normal decoupling did not occur. Thus, for example, the plug portion of the connector may have an inner member which is contained within a plug connector housing and which contains the actual plug or socket contacts of the connector, into which the corresponding socket or plug contacts of the receptacle member of the connector are inserted to accomplish the electrical connection by the connector. This inner portion has, in the past, been made releasable by providing a destructible emergency release mechanism, for example, a shearpin. The shearpin shears at an approximate force exerted in the decoupling procedure and is intended to allow the inner portion of the connector member to be removed from the connector housing upon the occurrence of a force, e.g., when a releasable pod is dropped from an aircraft wing and the pod weight is supported by the connector, if normal decoupling does not occur. Once the shearpin shears, the plug and receptacle connections of the connector are unmated, effecting disconnection of the connector.
Such destructible emergency release mechanisms suffer from several drawbacks, however. The first of these drawbacks is that the force exerted which will cause the shearpin to shear can vary with several factors, including a variation in the material from which the shearpin is constructed, manufacturing tolerances in the size of the shearpin, for example, in cross-sectional area, and several possible factors relating to the geometry of the connector and the manner in which the shear force is applied to the shearpin, for example, due to canting with respect to each other of the two members of the connector which are applying force to the shearpin. A second, and perhaps more serious drawback to the destructible type of emergency release mechanism is that the mechanism cannot be tested to determine the exact force at which the desired release will occur. A given destructible release mechanism may be tested, and a large number may also be tested to obtain data which may be helpful in estimating the effectiveness of the destructible release mechanism to release at the desired force or within the desired range of forces. However, for any given destructible release mechanism, the only effective test is one which results in the destruction of that particular destructible release mechanism.
Recognizing the shortcomings in the emergency release mechanisms previously utilized, e.g., for the protection of electrical connectors, it is the general object of the present invention to provide a non-destructible emergency release mechanism for electrical connectors, and other possible uses.
A feature of the present invention resides in the use of a spring mechanism which is positioned to hold two members of, e.g., an electrical connector which are moveable relative to each other in position within the connector and to resist motion of the one element with respect to the other in a decoupling direction until the force exerted on the spring exceeds a predetermined force. At this point, the spring, due to its structure, pops or flips to another position. This flipping or popping of the spring to the second position results in a decrease in the size of the outer perimeter of this spring. This decrease allows for the spring to clear retaining grooves in one or both of the two members such that the relative movement between the two members is no longer impeded.
Another feature of the present invention is the ability to adjust the force at which the release will occur or the range of forces within which the release will occur by modifying the shape of the spring, the thickness of the spring, or the material of the spring. Also, extension tabs may be provided as will be further described below.
It will be appreciated by those skilled in the art that the present invention provides a vast improvement over prior emergency release mechanisms of the destructible variety. The release mechanism of the present invention is easy to manufacture and to assemble into a completed connector. It is testable, in that it can be run through a number of cycles to determine whether the force at which the mechanical release occurs is within a desired range of forces such that the connector will not release inadvertently under normal operating or decoupling conditions, but will release at a force sufficiently low to insure disconnection. These and other features of the present invention will be better understood by reference to the detailed description of a preferred embodiment which follows: